The reason for the “powdering and sanding” on the surface of concrete often becomes a focus of controversy between construction units and commercial concrete enterprises: construction units believe that commercial concrete enterprises add mineral admixtures with poor water hardness and low density when producing concrete, which are prone to float to the surface of the concrete during vibration, resulting in a significant decrease in the surface hardness of the concrete and are the main culprits causing “powdering and sanding”; The “powdering and sanding” on the surface of concrete in commercial concrete enterprises is mainly caused by excessive vibration during the construction process, resulting in concrete bleeding.
The water cement ratio on the surface of the concrete is too high, the surface water strength is low, and the wear resistance is poor.
It is not related to the concrete material itself or whether it is mixed with fly ash, or improper curing of the concrete, resulting in rapid water loss and insufficient hydration of the surface cement.
.